1. Field of the Invention
The preset invention relates to a thermal transfer recording apparatus for image recording on a recording medium by ink transfer thereto from an ink sheet, and a facsimile apparatus utilizing said recording apparatus.
2. Related Background Art
In general, the thermal transfer recording apparatus effects image recording by employing an ink sheet obtained by coating a substrate film with thermally fusible ink, and selectively heating said ink sheet with a thermal recording head in response to image signals thereby transferring thus fused ink onto the recording sheet. Since such ink sheet is generally so-called one-time ink sheet in which the ink is completely transferred to the recording sheet in one recording, it is necessary, after the recording of a character or a line, to advance the ink sheet by a length corresponding to the recorded length, thereby securely bring an unused portion of the ink sheet to the position of next recording. This results in an increased amount of use of the ink sheet, and, for this reason the running cost of the thermal transfer recording apparatus has been significantly higher than that of the thermal recording apparatus.
In order to overcome this drawback, there is already proposed a thermal transfer recording apparatus employing so-called multi-print method, employing so-called multi-print ink sheet capable of image recordings of plural times in a same portion, and advancing the recording sheet and the ink sheet with a speed difference in such a manner that, during a recording of a length l on the recording sheet, the ink sheet is advanced by a smaller length l/n (n&gt;1).
However, such thermal transfer recording apparatus has been associated with a drawback that the quality of recorded image fluctuates according to the kind of recording medium, because, in energizing the motor for ink sheet advancement plural times, the number of pulses for said energization is determined not in consideration of the kind of recording medium. For example, in a recording medium with a relatively rough surface such as recycled paper, paper fibers protrude on the sheet surface, thereby forming a plurality of small irregularities. Therefore, when the ink is transferred onto the sheet surface, the peak portions of such small irregularities are not covered by ink, or, even if they are covered by ink, the ink will be rubbed off by the friction between the ink sheet and the recording sheet, thereby exposing the whiter peak portions and generating unevenness in density.